Scala List map() 方法与示例

map()方法用于将所述函数应用于列表的所有元素。

Method Definition: def map[B](f: (A) => B): List[B]

Return Type: It returns a new list after applying the stated function to all the elements of the list.

示例 #1：

// Scala program of map()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
        // Creating a list
        val m1 = List(2, 3, 5, 7, 8)
          
        // Applying map method
        val result = m1.map(x => x*3)
          
        // Displays output
        println(result)
      
    }
} 

输出：

List(6, 9, 15, 21, 24)

示例 #2：

// Scala program of map()
// method
  
// Creating object
object GfG
{ 
  
    // Main method
    def main(args:Array[String])
    {
        // Creating a list
        val m1 = List(2, 3, 5, 7, 8)
          
        // Applying map method
        val result = m1.map(x => x*x)
          
        // Displays output
        println(result)
      
    }
} 

输出：

List(4, 9, 25, 49, 64)